JPH07291600A - Safety device for track work vehicle - Google Patents

Abstract

PURPOSE:To prevent upsetting of a track work vehicle by a safety device of inexpensive and simple structure and widen a work area of a boom as wide as possible. CONSTITUTION:A right side detection circuit 31 is opened at a removed part when a vehicle receives an upsetting load, for example, when a left side rear wheel (a trail traveling wheel) 161' separates like floats from a rail R with which it was in contact (it is not upset but stability of a car body becomes lower) and thereby, current 11 will not be applied on this circuit. Thus, the current will not be applied in one of the detection circuit and actuation of a boom is regulated by a regulating means 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a track work vehicle that travels on a track to perform work, and more particularly to a safety device for ensuring work safety of the track work vehicle.

[0002]

2. Description of the Related Art A track work vehicle is equipped with wheels for running tracks on the front, rear, left and right sides of a vehicle body, and these wheels are mounted on two rails which are spaced apart from each other on the left and right sides. For example, track aerial work vehicles used for maintenance and inspection work of trolley wires (electric wires) stretched above rails for railroads are equipped with steel track wheels, and have horizontal turns and undulations on the vehicle body. It is equipped with a boom that can move freely, and a workbench for boarding workers is attached to the tip of this boom. By using such an aerial work vehicle for tracks, an operator can easily ascend to the vicinity of the trolley wire and can efficiently perform work.

By the way, the vehicle body of such an aerial work vehicle for orbit receives a tipping load (a moment acting in the tipping direction of the vehicle body) caused by the load at the tip of the boom, etc. When the tipping load becomes excessive, the vehicle body falls over. There is a danger of
Therefore, in a conventional track aerial work vehicle, a sensor and a calculator for calculating an actual tipping load, and the calculated actual load are set to the maximum allowable load (corresponding to the turning position of the boom). In many cases, a safety device is provided that includes a determiner that determines whether the load is greater than the maximum allowable load, and a limiting device that limits the boom operation when the actual load exceeds the maximum allowable load. . If such a safety device is used, a fall accident of the vehicle body can be reliably prevented, and the boom operation is regulated based on the actual fall load.
The work range of the boom can be extended to the maximum limit where there is a risk of tipping over the car body.

[0004]

However, such a safety device often has a complicated device configuration and is disadvantageous in terms of cost due to the use of relatively expensive components such as a computing unit and a judging unit. There is a problem that it is easy.

The present invention has been made in view of the above-mentioned problems, and is a safety of a track work vehicle in which the vehicle body can be prevented from tipping over with an inexpensive and simple structure and the work range of the boom can be expanded as much as possible. The purpose is to provide a device.

[0006]

In order to achieve the above object, a safety device of the present invention is provided with track running wheels made of a conductive material on the front, rear, left and right sides of a vehicle body, which are arranged apart from each other on the left and right sides.
These wheels are mounted on a rail made of a conductive material and mounted on a track work vehicle that travels. And this safety device
A left-side detection circuit formed by connecting two wheels provided on the left and right sides of the vehicle body in series via rails that contact these wheels, and a rail that connects two wheels provided on the right and left sides of the vehicle body to these wheels When the current stops flowing in at least one of the right detection circuit, the power supply that supplies a current to each of the left detection circuit and the right detection circuit, and the left detection circuit and the right detection circuit that are formed by connecting in series via And a regulation means for regulating the operation of the boom.

[0007]

In the safety device configured as described above, when the vehicle body receives a fall load and, for example, the left rear wheel (wheel for track running) floats away from the rail that has been in contact with it, Since the right side detection circuit is opened at the detached portion, no current flows through this circuit. In addition,
The situation in which one wheel floats from the rail in the aerial work vehicle for railroad tracks is because the stability of the vehicle body has become considerably low, although the vehicle cannot fall. In this way, when the current stops flowing through any of the detection circuits, the regulation means regulates the operation of the boom.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 show a bilateral aerial work vehicle equipped with a safety device according to the present invention. This railroad aerial work vehicle 10 is configured based on a truck traveling on a road. Therefore, tires (road wheels) are provided on the front, rear, left, and right of the vehicle body 11, respectively.
12 is attached. A swivel base 13 is attached to the front part of the vehicle body 11 so that it can swivel with respect to the vehicle body 11. A boom 14 configured to be telescopically expandable and retractable is pivotally attached to an upper portion of the swivel base 13 so as to be capable of undulating, and a work table 15 is attached to a tip of the boom 14. The workbench 15 is maintained horizontal by a leveling device (not shown) regardless of the up and down state of the boom 14.

Iron wheels (wheels for orbital running) 16 and 16 'are attached to the front, rear, left and right sides of the vehicle body 11 so that they can be extended (lowered) and stored (pulled up) by an iron wheel extension mechanism 17. The iron wheel overhanging mechanism 17 includes a support member 17a arranged on the vehicle body 11 and an iron wheel holding member 17b attached to a lower end portion of the support member 17a so as to be vertically swingable.
And a hydraulic expansion / contraction cylinder 17c that drives the iron wheel holding member 17b to vertically swing by expansion / contraction operation.
The iron wheel 16 is rotatably attached to the iron wheel holding member 17b while being electrically insulated from the member 17b. As shown in FIG. 2, the front left and right iron wheels 16l,
16r and the left and right iron wheels 16l ', 16r' on the rear side are connected by an axle 18. This axle 18
Left axle 18l '(18l) attached to left iron wheel 16l' (16l) and right iron wheel 16r '(16r)
The right axle 18r '(18r) attached to the vehicle is integrally connected with the electrically insulating material 18m interposed therebetween. A hydraulic center jack 19 that extends and contracts downward is attached to the front-rear intermediate portion on the lower side of the vehicle body 11.

An aerial work vehicle 1 for a land track constructed as described above.
0 is, first of all, rail for rail (hereinafter simply referred to as rail)
Travel along the road to a railroad crossing near the work site located along R. At this time, each iron wheel 16, 16 'is pulled up and stored with respect to the vehicle body 11 as shown by the chain line in the figure. When a railroad crossing near the work site is reached, the work vehicle 10 is stopped so as to cross the rail R on the railroad crossing. The stopped work vehicle 10 is the vehicle body 1
The center jack 19 attached to the center of the lower part of the vehicle 1 is extended downward to lift its own vehicle body 11. Then, the vehicle body 11 is turned around the center jack 19 so as to be parallel to the rail R, and the iron wheels 16 and 16 'are extended. Further, the center jack 19 is contracted to lower the vehicle body 11, and the iron wheels 16, 16 'and the rear wheels 12 are moved.
To contact the rail R.

Next, the rear wheels 12 can be driven to travel on the rail R to reach the work site. Then, the operator who rides on the workbench 15 operates an operating device (not shown) mounted on the workbench 15 to control the switching of the hydraulic control valve CV mounted on the side surface of the swivel base 13. The hydraulic control valve CV controls the supply / discharge of hydraulic oil to / from a hydraulic actuator that operates the swivel base 13 and the boom 14 according to the operation of the operating device. The car body 1
1 includes a hydraulic pump P that supplies hydraulic oil to the hydraulic control valve CV (see FIG. 3). In this way, the operator controls the operation of the boom 14 or the like to move the upper part of the rail R or the like.
It is possible to move to an arbitrary height and work on the trolley wire TL.

The aerial work vehicle 10 constructed as described above is equipped with the safety device of the present invention as described above.
The safety device will be described below with reference to FIG. The safety device 30 includes a left side detection circuit 31, a right side detection circuit 32, power sources B1 and B2, and an operation regulation circuit 33. The left-side detection circuit 31 includes front and rear left-side axles 1.
8l, 18l '(that is, left front wheel 16l and left rear wheel 16
1 '), the brush contacts 31a respectively contacting each other, the electric line 31c connecting the brush contacts 31a, the first power source B1 provided on the electric line 31c, and the electric line 31c provided on the electric line 31c. It comprises a power supply B1 and a relay coil CR connected in series. As can be seen from FIG. 2, the brush contact 31a includes the iron wheel holding member 1 through the holding member 31d made of an electrically insulating material.
It is held on the side surface of 7b that faces the inside of the vehicle body. As shown in FIG. 3, the brush contact 31a is formed in an inverted Y shape by back-to-back attaching the upper portions of two conductive plate members bent in a V shape. The axle is received inside the lower side (open portion) of the brush contact 31a, and the outer peripheral surface of the axle contacts the inner surface of the opened portion. As a result, the left detection circuit 31 is formed by connecting the left front wheel 16l and the left rear wheel 16l 'in series via the rail R that contacts them.

The right side detection circuit 32 is the left side detection circuit 3
As in the case of No. 1, the brush contacts 32a that come into contact with the front and rear right axles 18r and 18r ', and the brush contacts 32a
It is composed of an electric line 32c connecting between a and a. A second power source B2 and a relay coil CR are provided on the electric line 32c. That is, the right side detection circuit 32 is formed by connecting the right front wheel 16r and the right rear wheel 16r 'in series via the rail R that contacts them.

The operation restricting circuit 33 includes the unload valve 3
3a and a switch line 33b for controlling the switching of the unload valve 33a. The unload valve 33a is an electromagnetic control valve, and when the solenoid connected to the right end of the switch line 33b is in the non-excited state, it is offset to the left, and the hydraulic line L that connects the hydraulic pump P and the hydraulic control valve CV is connected. The hydraulic pump P is connected to the oil tank T while being shut off. on the other hand,
When the solenoid is energized and excited, the exciting force switches to the right movement position to open the hydraulic line L. On the switch line 33b, the switch line 3
A left-sided opening 33l and a right-sided opening 33r for opening and closing the intermediate portion of 3b are arranged in series with each other. Left door 33
Reference numeral 1 denotes a normally open type contact, which becomes close when the relay coil CR of the left side detection circuit 31 is energized and excited. Similarly, the right-side switch 33r is also a normally open type contact, and becomes a close when the relay coil CR of the right-side detection circuit 32 is energized and excited. The third power source B3 is attached to the left end of the switch line 33b.

Next, the safety device 30 constructed in this way
The operation of will be described. As shown in FIG.
The tipping moment M generated by the own weight of the boom 14 and the tip end load acts on this, but this tipping moment M is still present.
Is small and the vehicle body 11 is stable, all iron wheels 1
6 contacts the rail R. At this time, the left side detection circuit 31
A detection current I1 from the first power source B1 flows through the. Further, the detection current I2 also flows through the right side detection circuit 32 in the same manner. For this reason, the relay coils CR in the left and right detection circuits 31 and 32 are excited, and both the switches 33l and 33r in the operation regulation circuit 33 are closed.
The solenoid is excited by the current from 3, and the unload valve 33a is set to the right movement position. Therefore, an operator who has boarded the workbench 15 can control the operation of the boom 14 and the like by operating the operating device.

The overturning moment M increases and the vehicle body 11
When the iron wheel 16l 'on the left side floats (separates) from the rail R as shown in FIG. 4, the detection current I1 stops flowing in the left side detection circuit 31. In addition,
With one iron wheel floating in this way, the vehicle body 11 is still
However, there is some margin before actually falling. When the detection current I1 stops flowing, the relay coil CR of the left side detection circuit 31 is de-energized, and the left side switch 33l in the operation regulation circuit 33 is opened. Therefore, the solenoid is de-energized, the unload valve 33a is offset to the left position, and the hydraulic oil supply from the hydraulic pump P to the hydraulic control valve CV is stopped. Therefore,
Even if an operator on the workbench 15 operates the operation device,
The boom 14 and the like cannot be operated further in the direction in which the overturning moment M increases. It is desirable that the operating direction of the operating device (the operating direction of the boom 14 or the like) be detected so that the operating device can be operated in the direction in which the overturning moment M becomes smaller.

In the above embodiment, the case where the left side detection circuit 31 is cut off has been described, but the right side iron wheels 16r, 1
Even when 6r ′ floats from the rail R and the right side detection circuit 32 is cut off, the operation of the boom 14 and the like is similarly restricted.

[0018]

As described above, in the safety device of the present invention, a series circuit is formed on each of the left and right sides of the vehicle body by the front and rear track traveling wheels and the tracks in contact with these wheels, and a detection current is passed therethrough. . When the detection current stops flowing, the stability of the vehicle body is lowered, and it is detected that one of the wheels is lifted from the track, and the operation of the boom is restricted. Therefore, by using the present safety device, it is possible to prevent a vehicle body overturn accident with a simple and inexpensive device configuration without using sensors or a computing unit. Furthermore, with this safety device, the boom operation is restricted after the stability of the vehicle body actually decreases, so the working range of the boom attached to the vehicle body should be expanded to the maximum limit according to the size of the tip load. You can

[Brief description of drawings]

FIG. 1 is a side view of a road-rail amphibious work vehicle equipped with a safety device according to the present invention.

FIG. 2 is a rear view of the aerial work vehicle.

FIG. 3 is a configuration diagram of the safety device.

FIG. 4 is an operation explanatory view of the safety device.

[Explanation of symbols]

 10 Road-rail aerial work vehicle 14 Boom 16 Iron wheel (wheel for track running) 30 Safety device 31, 32 Detection circuit 31a, 32a Brush contact 33 Operation restriction circuit 33a Unload valve B1, B2, B3 Power supply R Railway rail TL trolley line

Claims (1)

[Claims] 1. A vehicle body is provided with a boom that can be raised and lowered, and front and rear and right and left sides of the vehicle body are provided with wheels for track running made of a conductive material, and these wheels are mounted on two rails made of a conductive material that are arranged apart from each other on the left and right sides. A left side detection circuit formed by connecting the two wheels provided on the front and rear of the left side of the vehicle body in series via the rails in contact with these wheels; A right-side detection circuit formed by connecting the two wheels provided on the front and rear of the right side of the vehicle body in series via the rails in contact with these wheels, and a current flows through each of the left-side detection circuit and the right-side detection circuit. A power source; and a regulation unit that regulates the operation of the boom when current stops flowing in at least one of the left side detection circuit and the right side detection circuit. The safety device of the track work vehicle to the butterfly.